/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.iotdb.kafka;

import org.apache.iotdb.rpc.IoTDBConnectionException;
import org.apache.iotdb.rpc.StatementExecutionException;
import org.apache.iotdb.session.pool.SessionPool;
import org.apache.iotdb.tsfile.file.metadata.enums.CompressionType;
import org.apache.iotdb.tsfile.file.metadata.enums.TSDataType;
import org.apache.iotdb.tsfile.file.metadata.enums.TSEncoding;
import org.apache.kafka.clients.consumer.ConsumerConfig;
import org.apache.kafka.clients.consumer.KafkaConsumer;
import org.apache.kafka.common.serialization.StringDeserializer;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Properties;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

/**
 * The class is to show how to get data from kafka through multi-threads. The data is sent by class
 * Consumer.
 */
public class Consumer {

    private List<KafkaConsumer<String, String>> consumerList;
    private static final Logger logger = LoggerFactory.getLogger(Consumer.class);
    private static SessionPool pool;

    private Consumer(List<KafkaConsumer<String, String>> consumerList) {
        this.consumerList = consumerList;
        pool =
                new SessionPool.Builder()
                        .host(Constant.IOTDB_CONNECTION_HOST)
                        .port(Constant.IOTDB_CONNECTION_PORT)
                        .user(Constant.IOTDB_CONNECTION_USER)
                        .password(Constant.IOTDB_CONNECTION_PASSWORD)
                        .maxSize(Constant.SESSION_SIZE)
                        .build();
    }

    public static void main(String[] args) {
        List<KafkaConsumer<String, String>> consumerList = new ArrayList<>();
        for (int i = 0; i < Constant.CONSUMER_THREAD_NUM; i++) {

            /** Consumer configuration */
            Properties props = new Properties();

            props.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, Constant.KAFKA_SERVICE_URL);
            /** serializer class */
            props.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class);
            props.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class);
            /**
             * What to do when there is no initial offset in ZooKeeper or if an offset is out of range
             * earliest: automatically reset the offset to the earliest offset latest:automatically reset
             * the offset to the latest offset
             */
            props.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "earliest");
            /** There is only one consumer in a group */
            props.put(ConsumerConfig.GROUP_ID_CONFIG, Constant.TOPIC);

            KafkaConsumer<String, String> consumer = new KafkaConsumer<>(props);
            consumerList.add(consumer);
            consumer.subscribe(Collections.singleton(Constant.TOPIC));
        }
        Consumer consumer = new Consumer(consumerList);
        initIoTDB();
        consumer.consumeInParallel();
    }

    @SuppressWarnings("squid:S2068")
    private static void initIoTDB() {

        try {
            for (String storageGroup : Constant.STORAGE_GROUP) {
                addStorageGroup(storageGroup);
            }
            for (String[] sql : Constant.CREATE_TIMESERIES) {
                createTimeseries(sql);
            }
        } catch (IoTDBConnectionException | StatementExecutionException e) {
            logger.error(e.getMessage());
        }
    }

    private static void addStorageGroup(String storageGroup)
            throws IoTDBConnectionException, StatementExecutionException {
        pool.setStorageGroup(storageGroup);
    }

    private static void createTimeseries(String[] sql)
            throws StatementExecutionException, IoTDBConnectionException {
        String timeseries = sql[0];
        TSDataType dataType = TSDataType.valueOf(sql[1]);
        TSEncoding encoding = TSEncoding.valueOf(sql[2]);
        CompressionType compressionType = CompressionType.valueOf(sql[3]);
        pool.createTimeseries(timeseries, dataType, encoding, compressionType);
    }

    private void consumeInParallel() {
        /** Specify the number of consumer thread */
        ExecutorService executor = Executors.newFixedThreadPool(Constant.CONSUMER_THREAD_NUM);
        for (int i = 0; i < consumerList.size(); i++) {
            ConsumerThread consumerThread = new ConsumerThread(consumerList.get(i), pool);
            executor.submit(consumerThread);
        }
    }
}
